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Twentymile Coal, LLC (TC) <br />Geologic and Engineering Data Report <br />Lease by Modification Application — Wolf Creek Reserve April 2014 <br />No significant acid-forming, toxic -forming, or alkalinity -producing materials have been identified within the <br />coal seam or associated overburden units. <br />The quality results noted in Table 1 are from as -received proximate analysis taken from the 2013 and 2014 <br />drill holes located in and adjacent to the lease modification area. TC also completed additional drilling and <br />sampling during 2013 and 2014, and additional quality data from these drillholes should be available during <br />second quarter 2014. Refer to the Table 1 at the end of this report and Plate 3 for drillhole locations and <br />quality summary. <br />D. Coal quantity by bed <br />Average thickness <br />The Wolf Creek Seam ranges in thickness from 7.5 to 10.5 feet within the mine plan area. Refer to <br />Plate 5 — Coal Thickness drawing. <br />2. Tonnage <br />a. In -Place coal <br />The estimated mineable reserves for the 460 acres that fall within both the 760 -acre lease <br />modification area and the Wolf Creek Reserve mine plan area were calculated to be 7,648,000 tons. <br />Refer to Plate 5 — Coal Thickness drawing and Plate 7 — Mine Plan drawing. <br />b. Recoverable coal <br />Due primarily to the coal seam configuration, and limitations imposed by faults and the three <br />partings within the Wolf Creek Reserve mine plan area, the recoverable coal reserves within the <br />lease modification area are estimated at 5,144,000 tons. This estimate was calculated by subtracting <br />roof and floor material, areas where the individual benches pinch -out, and areas where the partings <br />render one or more benches unminable. <br />Recoverable reserves were calculated by the BLM and checked against the TC estimate. The BLM <br />calculation used the proposed 542 -acre mining plan perimeter submitted by TC in order to arrive at <br />this recoverable reserve figure. Development and Longwall barrier pillar areas were first subtracted <br />from the total mine plan perimeter and a 9.5' average recoverable thickness was applied. A <br />recovery factor of 73.7% was used for the remaining areas of entries and longwall panels. Overall <br />recovery (tons recovered/tons in-place) in the 460 -acre mined portion of the lease area should be <br />around 67.3%, a reasonable recovery ratio for the combination of underground methods to be <br />employed in this area of coal pinch -outs, partings and unminable benches. <br />E. Additional data <br />Hydrologic data and problems <br />There are identified Alluvial Valley Floor (AVF) areas along Fish Creek which overlie the Wolf <br />Creek Reserve area; however, TC has already successfully undermined these areas without <br />significant impact on the essential hydrologic function. There is also an accumulation of water in a <br />portion of the overlying Wadge Seam workings which will need to be drained prior to undermining <br />this area. TC plans to drain this water and transfer it to other areas of sealed mine workings in the <br />Western Mining District. Refer to Plate 2, Map 23 for location. <br />Geologic data and problems <br />a. Isopachs (Overburden, Interburden, Coal) - Refer to Plate 6 for overburden thickness, Figure <br />WCR BLM Lease App Geologic & Engineeering Data Report 0414.docx Page 2 <br />